Vehicle information transmission device

ABSTRACT

A vehicle information transmission device prompts recognition of a certain object. The vehicle information transmission device prompts recognition of a position different from a position of the certain object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a vehicle information transmission device.

2. Description of Related Art

Japanese Patent Application Publication No. 2010-176591(JP-A-2010-176591) describes a vehicle display device that causes afront windshield to reflect light from LEDs to transmit information to adriver. Japanese Patent Application Publication No. 2000-172994(JP-A-2000-172994) describes a vehicle obstacle warning device that,when an obstacle has been detected on the right side or left side of thevehicle, individually changes the sizes or luminances of right and leftwarning displays. Japanese Patent No. 3626229 describes a vehicle drivesupport system that projects light from light sources installed in avehicle so that light is reflected at a position on the surface of afront windshield, which corresponds to a detected position of a riskoutside the vehicle, to inform a driver of the risk.

However, the techniques described in JP-A-2010-176591, JP-A-2000-172994and Japanese Patent No. 3626229 still have room for improvement in termsof the way of information transmission.

SUMMARY OF THE INVENTION

The invention provides a vehicle information transmission device thatcarries out better information transmission for a driver.

A first aspect of the invention relates to a vehicle informationtransmission device that prompts recognition of a certain object. Thevehicle information transmission device prompts recognition of aposition different from a position of the certain object. Note that, inthe above aspect, the position of the certain object and the positiondifferent from the position of the certain object may be spaced apartfrom each other. In addition, a manner of prompting recognition of thecertain object may be different from a manner of prompting recognitionof the position different from the position of the certain object. Inaddition, in a case where the position of the certain object is a leftside when viewed from a driver, the position different from the positionof the certain object may be a right side when viewed from the driver;and in a case where the position of the certain object is the right sidewhen viewed from the driver, the position different from the position ofthe certain object may be the left side when viewed from the driver. Inaddition, the vehicle information transmission device may promptrecognition of the position different from the position of the certainobject while prompting recognition of the certain object.

A second aspect of the invention relates to a vehicle informationtransmission device that includes: a first display portion that promptschecking of a right side when viewed from a driver; and a second displayportion that prompts checking of a left side when viewed from thedriver. When checking of a certain object is prompted at the right sideor at the left side, the first display portion and the second displayportion respectively prompt checking of the right side and checking ofthe left side. A third aspect of the invention relates to a vehicleinformation transmission device that includes a display device thatdisplays a virtual image at each of a plurality of positions on a frontwindshield or a rear windshield. When the display device displays thevirtual image at a certain position in order to prompt a driver torecognize a certain object, the display device displays the virtualimage also at a position different from the certain position.

According to the above aspects of the invention, not only recognition ofa certain object but also recognition of a position different from theposition of the certain object is prompted, so it is possible to carryout better information transmission for a driver.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the invention will be described below withreference to the accompanying drawings, in which like numerals denotelike elements, and wherein:

FIG. 1 is a block diagram that shows an example of the configuration ofa vehicle information transmission system according to an embodiment;

FIG. 2 is a view that shows an example of the configuration of a lightsource panel;

FIG. 3 is a view that shows an example of the configuration of a lightsource panel;

FIG. 4 is a view that shows an example of the configuration of a lightsource panel;

FIG. 5 is a view that shows an example of a position at which the lightsource panel is mounted;

FIG. 6 is a view that shows an example of the definition of an eyepoint;

FIG. 7 is a view that shows an example of a position at which the lightsource panel is mounted;

FIG. 8 is a view that shows an example of a position at which the lightsource panel is mounted;

FIG. 9 is a view that shows an example of a position at which the lightsource panel is mounted;

FIG. 10 is a view that shows an example of a range indicated by avirtual image when viewed from above a vehicle;

FIG. 11 is a view that shows an example of a method of adjusting thecolor and luminance of light from each of light sources;

FIG. 12 is a view that shows an example of a map that defines thecorrelation between a distance and a color/luminance and an example of amap that defines the correlation between an angle and a color/luminance;

FIG. 13 is a view that shows an example of a map that defines thecorrelation between a body color and a normal color, reminding color,warning color and luminance;

FIG. 14 is a view that shows an example of the way of showing a virtualimage;

FIG. 15 is a view that shows an example of the way of showing a virtualimage;

FIG. 16 is a view that shows an example of the way of showing a virtualimage;

FIG. 17 is a view that shows an example of the way of showing a virtualimage;

FIG. 18 is a view that shows an example of the way of showing a virtualimage;

FIG. 19 is a view that shows an example of the way of showing a virtualimage;

FIG. 20 is a view that shows an example of the way of showing a virtualimage;

FIG. 21 is a flowchart that shows an example of risk computing operationand lighting control operation that are executed by the vehicleinformation transmission system according to the embodiment;

FIG. 22 is a view that shows an example of a map that defines thecorrelation between the position and degree of risk of an object and theprojected position and projected area of light;

FIG. 23 is a graph that shows an example of the correlation between thedegree of risk and the rate of variation per unit variation in the coloror luminance of light;

FIG. 24 is a view that shows an example of the way of showing a virtualimage;

FIG. 25 is a view that shows an example of the way of showing a virtualimage;

FIG. 26 is a view that shows an example of the way of showing a virtualimage;

FIG. 27 is a view that shows an example of the way of showing a virtualimage;

FIG. 28 is a view that shows an example of the way of showing a virtualimage;

FIG. 29 is a view that shows an example of the way of showing a virtualimage; and

FIG. 30 is a view that shows an example of the way of showing a virtualimage.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, a vehicle information transmission system that includes avehicle information transmission device according to an embodiment ofthe invention will be described in detail with reference to theaccompanying drawings. Note that the aspect of the invention is notlimited by this embodiment.

The vehicle information transmission system according to the presentembodiment projects light from a plurality of light sources(light-emitting diodes (LEDs)) mounted (arranged) in an array (aplurality of rows or a plurality of columns) at an instrument panel,onto a front windshield to notify (remind or warn) a driver of aposition at which a risk object (such as a pedestrian, a bicycle, anautomobile and a blind spot) around a host vehicle is present or adirection in which the risk object is present with a virtual image madefrom the projected light. Hereinafter, an example of the configurationof this system, an example of the operation executed by this system, andthe like, will be described in detail with reference to the accompanyingdrawings.

Note that, in the following description, a position at which the lightsources are mounted is set at the instrument panel; instead, theposition may be, for example, set at a meter panel, or the like. Inaddition, the light sources are single-color LEDs; instead, the lightsources may be, for example, full-color LEDs, bulbs, or the like. Inaddition, a portion onto which light is projected (a portion on which avirtual image is displayed) is the front windshield; instead, theportion may be, for example, an A pillar, a sideview mirror, the meterpanel, the instrument panel, or the like. In addition, details notifiedto the driver contain a risk object (risk); instead, the details may,for example, contain a route guidance, an arrival of an e-mail, thecondition of the driver (such as waking and sleeping), the condition ofthe host vehicle (such as an eco-driving condition), or the like. Inaddition, a risk object is detected by an object sensor; instead, a riskobject may be, for example, detected by image recognition using acamera, communication, such as inter-vehicle communication androad-to-vehicle communication, navigation information (such as a map anda database about risky places, or the like), or the like. In addition,the position and direction for which a notification is provided are leftand right when viewed from the driver; instead, the position anddirection may be, for example, front and rear, or the like. In addition,the shape of a displayed virtual image is a linear shape (dot sequence);instead, the shape may be, for example, a graphic such as an icon, acharacter, a symbol, or the like. In addition, other than a notificationof a position at which a risk object is present or a direction in whicha risk object is present, the details (such as information that the riskobject is a pedestrian, a bicycle, an automobile or a blind spot), orthe like, of the risk object may also be notified. In addition, the modeof notification (the form of notification and the way of notification)is light; instead, the mode of notification may be, for example, anyhuman recognizable mode, such as sound (voice) and operation reactionforce.

1. Configuration

FIG. 1 is a block diagram that shows an example of the configuration ofthe vehicle information transmission system according to the presentembodiment. A vehicle 1 includes a light source panel 10, an objectsensor 11, a driver sensor 12, a vehicle speed sensor 13, an electroniccontrol unit (ECU) 14, a lighting control unit 15 and a lighttransmission control unit 16. The light source panel 10 has a pluralityof light sources 10 a and a mechanism that adjusts the degree oftransmission of light and luminance of light from the light sources 10a. The ECU 14 includes a risk computing unit 14 a. The light sourcepanel 10 may be regarded as a display device according to the aspect ofthe invention.

The object sensor 11 detects an external environment (information aboutan object, such as a pedestrian, a bicycle, an automobile and a blindspot (such as a spot behind a building, the blind side of a curve andthe blind side of a vehicle), a road shape, such as a straight road, aleft-hand curve and a right-hand curve) around the vehicle 1. The driversensor 12 detects driver's point of gaze and direction of gaze. Thevehicle speed sensor 13 detects the speed of the vehicle 1. The riskcomputing unit 14 a computes (estimates) the degree of risk around thevehicle 1 on the basis of the external environment around the vehicle 1detected by the object sensor 11, the point of gaze and direction ofgaze detected by the driver sensor 12, the vehicle speed detected by thevehicle speed sensor 13, and the like.

FIG. 2 is a view that shows an example of the configuration of the lightsource panel 10. As shown in FIG. 2, the light source panel 10 includesa diffuser panel 10 b, a shaft member 10 c and springs 10 d. In thelight source panel 10, the plurality of light sources 10 a are arrangedin an array of a plurality of rows or plurality of columns so that lightmay be emitted in a lateral direction (horizontal direction,vehicle-width direction) and a longitudinal direction (height direction,vertical direction). In order to project three red, yellow and greenhorizontal line virtual images on the front windshield from top, thelight source panel 10 is installed so that the light sources 10 a thatemit red series light are arranged in a line near the driver, the lightsources 10 a that emit yellow series light are arranged in a middle lineand then the light sources 10 a that emit green series light arearranged in a far-side line. In the light source panel 10, the diffuserpanel 10 b and the shaft member 10 c are used to entirely or partiallyadjust the degree of transmission of light (the degree of blur oflight/the degree of diffusion of light) from the light sources 10 a inassociation with the positions of the light sources 10 a, and theplurality of springs 10 d are used to keep the distance between thelight sources' 10 a and the diffuser panel 10 b maximal in the event ofa failure. The plurality of springs 10 d serve as a fail-safe device. Anactuator (not shown) such as a motor is arranged in the light sourcepanel 10. The actuator electromagnetically or electrically carries outthree rotational movements (vertical, horizontal and twistingmovements), that is, the pitch, yaw and roll, of the diffuser panel 10b. The diffuser panel 10 b is, for example, formed of a thin platemember made of a material, such as polypropynene and polycarbonate. Theshaft member 10 c is a shaft member that serves as an axis of threerotational movements of the diffuser panel 10 b. Note that the positionsof the springs 10 d or the number of the springs 10 d may be set so asto be able to keep the distance between the light sources 10 a and thediffuser panel 10 b maximal in the event of a failure. In addition, inorder to expand light to a wider range, Fresnel lens may be insertedabove or below the diffuser panel 10 b.

FIG. 3 is a view that shows another example of the configuration of thelight source panel 10. As shown in FIG. 3, the light source panel 10includes light guide members 10 e. The diffuser panel 10 b and the lightguide members 10 e are arranged in the light source panel 10. Thediffuser panel 10 b and the light guide members 10 e are used to adjustthe degree of transmission of light from the light sources 10 a. Thelight guide members 10 e are, for example, optical fibers, or the like,and are arranged individually in correspondence with the light sources10 a as shown in the drawing. An actuator (not shown) is arranged in thelight source panel 10. The actuator adjusts the distance between thediffuser panel 10 b and the light guide members 10 e. With theconfiguration shown in FIG. 3, the degree of transmission of light fromeach of the light sources 10 a may be adjusted independently of oneanother.

FIG. 4 is a view that shows another example of the configuration of thelight source panel 10. As shown in FIG. 4, the light source panel 10includes a liquid crystal panel 10 f. The liquid crystal panel 10 f isarranged in the light source panel 10 in a state where the distance fromthe light sources 10 a are fixed. The liquid crystal panel 10 f is usedto adjust the degree of transmission of light from the light sources 10a. With the configuration shown in FIG. 4, the aperture ratio of theliquid crystal panel 10 f is decreased from the center toward theperiphery to make it possible to blur light.

FIG. 5 is a view that shows an example of a position at which the lightsource panel 10 is mounted in the vehicle 1. As shown in FIG. 5, thereference numeral 20 denotes a front windshield that has a ghostreduction structure, such as a tapered glass, the reference numeral 21denotes a hood, the reference numeral 22 denotes an instrument panel,the reference numeral 23 denotes a meter panel, the reference numeral 24denotes a steering wheel, the reference numeral 30 denotes a driver'seye point, the reference numeral 31 denotes a virtual image formed bylight from the light source panel 10, the reference numeral 32 denotes ahorizontal line that passes through the eye point 30, and the referencenumeral 33 denotes the optical path of light from the light source panel10. The light source panel 10 is installed on the instrument panel 22,and is specifically installed at a position such that the virtual image31 may be recognized by the driver in the lowermost region (for example,the depression angle α from the horizontal line 32 that passes throughthe eye point 30 is smaller than or equal to five degrees) of aperipheral visual field of the driver. For example, the light sourcepanel 10 is installed at a position that is closer to the frontwindshield 20 than to the meter panel 23 (in other words, the far sideof the instrument panel 22 from the eye point 30). Here, as shown inFIG. 6, the eye point 30 is set at a height of 635 (mm) vertically abovea seating reference point 36 that is the hip joint point of a humanphantom when the human phantom is seated on a seat in compliant withISO6549-1980 (see “Notice that regulates the particulars of safetystandard for road trucking vehicles [2005 Nov. 9], enclosure 81,(Technical Standard Order for Front and Left-Side Under Mirror)described in the homepage address“http://www.mlit.go.jp/jidosha/kijyun/saimokubetten/saibet_(—)081_(—)00.pdf”).

FIG. 7 and FIG. 8 are views that show other examples of positions atwhich the light source panel 10 is mounted in the vehicle 1. In FIG. 7and FIG. 8, the reference numeral 25 denotes a defroster outlet portion.For example, the light source panel 10 is installed at a portion on thenear side (see FIG. 7) or far side (see FIG. 8) of the defroster outletportion 25 when viewed from the eye point 30. For example, the lightsource panel 10 is installed under the surface of the instrument panel22 (in other words, inside the instrument panel 22). For example, thelight source panel 10 is embedded in the instrument panel 22.

FIG. 9 is a view that shows an example of a position at which the lightsource panel 10 is mounted in the vehicle 1. In FIG. 9, the referencenumeral 26 denotes a rearview mirror, the reference numeral 27 denotes Apillars, and the reference numeral 34 denotes the driver's direction ofgaze. For example, the light source panel 10 is installed at a positionthat is substantially ahead of the driver on the instrument panel 22.The light source panel 10 is installed on the instrument panel 22 sothat the background of the virtual image 31 is, for example, a forwardview (such as a road or a preceding vehicle) when viewed from the eyepoint 30.

FIG. 10 is a view that shows an example of the range indicated by thevirtual image 31 when viewed from above the vehicle 1. When the vehicle1 in which the light source panel 10 is mounted on the instrument panel22 as described above is, for example, present on a road with a sidewalkwidth of 1 (m) and a lane width of 3.2 (m), the range indicated by thevirtual image 31 (the range for a risk object) when viewed from the eyepoint 30 is the illustrated range between a point 8.1 (m) ahead of thevehicle 1 on the left side to a point 22.5 (m) ahead of the vehicle 1 onthe right side.

Referring back to FIG. 1, the lighting control unit 15 sets a normal,reminding or warning lighting pattern (lighting details or lighting moderegarding the position onto which light is projected on the frontwindshield 20, the area in which light is projected on the frontwindshield 20, the color of light, the luminance of light, the interval(blinking) of light, the amount of variation per unit variation in thecolor or luminance of light (the amount of unit variation in color orluminance), or the like) on the basis of the external environment aroundthe vehicle 1, which is detected by the object sensor 11, the driver'spoint of gaze or direction of gaze detected by the driver sensor 12, thespeed of the vehicle 1, which is detected by the vehicle speed sensor13, the degree of risk around the vehicle 1, which is computed by therisk computing unit 14 a, and the like, and the lighting control unit 15executes lighting control (for example, adjusting an applied voltage, orthe like) over the individual light sources 10 a so as to attain the setlighting pattern.

Here, an example of an adjusting (calibration) method for the color andluminance of light from the light sources 10 a will be described withreference to FIG. 11 to FIG. 13. As shown in FIG. 11, the color andluminance of light from the individual light sources 10 a are adjustedin advance on the basis of a distance L and/or an angle θ. For example,the color and luminance of light from the individual light sources 10 aare adjusted on the basis of a map (see FIG. 12) that defines thecorrelation between a distance L and a color/luminance and/or a map (seeFIG. 12) that defines the correlation between an angle θ and acolor/luminance. Here, the distance L is a distance from the lightsource 10 a to the corresponding position onto which light from thelight source 10 a is projected on the front windshield 20. As shown inFIG. 12, the lighting control unit 15 increases the luminance of lightfrom the light source 10 a as the distance L increases. The angle θ isan angle formed by the front windshield 20 and the line segment thatconnects the position at which the light source 10 a is arranged and thecorresponding position onto which light is projected. As shown in FIG.12, the lighting control unit 15 decreases the luminance of light fromthe light source 10 a as the angle θ increases. The front windshield 20may be regarded as “a portion of the vehicle body, onto which light isprojected” according to the invention. In addition, the color andluminance of each of the light sources 10 a during normal times, duringreminding and during warning are, for example, adjusted in advance onthe basis of the color of the instrument panel, A pillar, sideviewmirror, or the like. For example, the color and luminance of each of thelight sources 10 a during normal times, during reminding and duringwarning are adjusted on the basis of a map (see FIG. 13) that definesthe correlation between a body color and a normal color, remindingcolor, warning color and luminance. These adjusted statuses of the colorand luminance are stored in the storage area of the lighting controlunit 15.

Note that the lighting control unit 15 may adjust the luminance or colorof light based on whether a head light is on or off, or using a photodetecting sensor or the like. For example, the lighting control unit 15may decrease the luminance of light during nighttime hours. In addition,the lighting control unit 15 may adjust the luminance, color, interval(blinking), and the like, of light on the basis of the reliability ofthe degree of risk estimated by the risk computing unit 14a. Inaddition, the lighting control unit 15 may stop rays of light recognizedby the driver among the lighted rays of light or reduce the luminance,color, or the like, of the recognized rays of light on the basis of thedriver's point of gaze or direction of gaze detected by the driversensor 12. In addition, the lighting control unit 15 may also notify thedetails of a risk object (for example, the risk object is a pedestrian,a vehicle, or the like) together with the position at which the riskobject is present or the direction in which the risk object is present.

Referring back to FIG. 1, the light transmission control unit 16 adjuststhe degree of transmission (the degree of blur/the degree of diffusion)of light from the light sources 10 a of the light source panel 10 on thebasis of the external environment around the vehicle 1, which isdetected by the object sensor 11, the driver's point of gaze ordirection of gaze detected by the driver sensor 12, the speed of thevehicle 1, which is detected by the vehicle speed sensor 13, the degreeof risk around the vehicle 1, which is computed by the risk computingunit 14, the light pattern set by the lighting control unit 15, and thelike.

For example, when the lighting control unit 15 lights the light sources10 a in the reminding lighting pattern, the light transmission controlunit 16 increases the distance between the light sources 10 a and thediffuser panel 10 b in the light source panel 10 as a whole when thelight source panel 10 shown in FIG. 2 is used, increases the distancebetween the diffuser panel 10 b and the light guide members 10 e in thelight source panel 10 as a whole when the light source panel 10 shown inFIG. 3 is used or decreases the aperture ratio of the liquid crystalpanel 10 f in the light source panel 10 as a whole when the light sourcepanel 10 shown in FIG. 4 is used. By so doing, the state of the virtualimage 31 may be changed from the clear state shown in FIG. 14 to theblurry state shown in FIG. 15. That is, the virtual image 31 may beblurred.

In addition, on the basis of the degree of risk computed by the riskcomputing unit 14 a, the light transmission control unit 16 adjusts thedistance between the light sources 10 a and the diffuser panel 10 b whenthe light source panel 10 shown in FIG. 2 is used, adjusts the distancebetween the diffuser panel 10 b and the light guide members 10 e whenthe light source panel 10 shown in FIG. 3 is used or adjusts theaperture ratio of the liquid crystal panel 10 f when the light sourcepanel 10 shown in FIG. 4 is used. When the degree of risk is low, thelight transmission control unit 16 increases the distance between thelight sources 10 a and the diffuser panel 10 b as a whole, increases thedistance between the diffuser panel 10 b and the light guide members 10e as a whole or decreases the aperture ratio of the liquid crystal panel10 f as a whole. In addition, when the degree of risk is high, the lighttransmission control unit 16 reduces the distance between the lightsources 10 a and the diffuser panel 10 b as a whole, reduces thedistance between the diffuser panel 10 b and the light guide members 10e as a whole or increases the aperture ratio of the liquid crystal panel10 f as a whole. By so doing, the clear virtual image 31 may bedelivered when the risk is high; whereas the blurry virtual image 31 maybe delivered when the risk is low.

In addition, when the lighting control unit 15 lights the light sources10 a in a lighting pattern that displays specific information (such as acharacter and an icon), the light transmission control unit 16 reducesthe distance between the light sources 10 a and the diffuser panel 10 bin the light source panel 10 as a whole when the light source panel 10shown in FIG. 2 is used, reduces the distance between the diffuser panel10 b and the light guide members 10 e in the light source panel 10 as awhole when the light source panel 10 shown in FIG. 3 is used orincreases the aperture ratio of the liquid crystal panel 10 f in thelight source panel 10 as a whole when the light source panel 10 shown inFIG. 4 is used. By so doing, the clear virtual image 31 corresponding tothe specific information may be delivered.

In addition, on the basis of the speed of the vehicle 1 detected by thevehicle speed sensor 13, the light transmission control unit 16 adjuststhe distance between the light sources 10 a and the diffuser panel 10 bwhen the light source panel 10 shown in FIG. 2 is used, adjusts thedistance between the diffuser panel 10 b and the light guide members 10e when the light source panel 10 shown in FIG. 3 is used or adjusts theaperture ratio of the liquid crystal panel 10 f when the light sourcepanel 10 shown in FIG. 4 is used. When the vehicle speed is lower thanor equal to a predetermined value (for example, when the vehicle 1 isstopped, or the like), the light transmission control unit 16 reducesthe distance between the light sources 10 a and the diffuser panel 10 bas a whole, reduces the distance between the diffuser panel 10 b and thelight guide members 10 e as a whole or increases the aperture ratio ofthe liquid crystal panel 10 f as a whole. On the other hand, when thevehicle speed exceeds the predetermined value (for example, when thevehicle 1 is running, or the like), the light transmission control unit16 increases the distance between the light sources 10 a and thediffuser panel 10 b as a whole, increases the distance between thediffuser panel 10 b and the light guide members 10 e as a whole ordecreases the aperture ratio of the liquid crystal panel 10 f as awhole. By so doing, the clear virtual image 31 shown in FIG. 16 may bedelivered when the vehicle 1 is stopped; whereas the blurry virtualimage 31 shown in FIG. 17 may be delivered when the vehicle 1 isrunning.

In addition, when the light source panel 10 shown in FIG. 2 is used, thelight transmission control unit 16 partially increases the distancebetween the light sources 10 a that project light to around a driver'spoint of gaze 38 detected by the driver sensor 12 and only part of thediffuser panel 10 b, which corresponds to the positions at which thoselight sources 10 a are arranged. When the light source panel 10 shown inFIG. 3 is used, the light transmission control unit 16 partiallyincreases the distance between the diffuser panel 10 b and only part ofthe light guide members 10 e, which are arranged in correspondence withthe light sources 10 a that project light to around the point of gaze 38(see FIG. 18). When the light source panel 10 shown in FIG. 4 is used,the light transmission control unit 16 decreases the aperture ratio ofonly part of the liquid crystal panel 10 f, which corresponds to thepositions at which the light sources 10 a that project light to aroundthe point of gaze 38 are arranged. By so doing, as shown in FIG. 18,only part of the virtual image 31 viewed by the driver (part of thevirtual image 31 around the point of gaze 38) may be selectively blurredand delivered in the blurry state.

In addition, the light transmission control unit 16 adjusts the degreeof transmission of light from the light sources 10 a of the light sourcepanel 10 on the basis of a road shape, such as a left-hand curve and aright-hand curve. When the light source panel 10 shown in FIG. 2 isused, the light transmission control unit 16 partially increases thedistance between the light sources 10 a that project light toward adirection (for example, right-hand direction for a right-hand curve, aleft-hand direction for a left-hand curve) in which the road shapechanges and in which the driver gazes and only part of the diffuserpanel 10 b, which corresponds to the positions at which those lightsources 10 a are arranged. When the light source panel 10 shown in FIG.3 is used, the light transmission control unit 16 partially increasesthe distance between the diffuser panel 10 b and only part of the lightguide members 10 e, which are arranged in correspondence with the lightsources 10 a that project light toward a direction in which the roadshape changes. When the light source panel 10 shown in FIG. 4 is used,the light transmission control unit 16 decreases the aperture ratio ofonly part of the liquid crystal panel 10 f, which corresponds to thepositions at which the light sources 10 a that project light toward adirection in which the road shape changes are arranged. By so doing, asshown in FIG. 19, only part of the virtual image 31 in the curvedirection in which the driver gazes (part of the virtual image 31 aroundthe direction of gaze 34) may be selectively blurred and delivered inthe blurry state.

In addition, the light transmission control unit 16 adjusts the degreeof transmission of light from the light sources 10 a of the light sourcepanel 10 on the basis of the distance from a driver's central visualfield (the driver's point of gaze 38 detected by the driver sensor 12(see FIG. 20)) to the virtual image 31. When the light source panel 10shown in FIG. 2 is used, the light transmission control unit 16relatively increases the distance between the diffuser panel 10 b andthe light sources 10 a having a relatively short distance from the pointof gaze 38, relatively reduces the distance between the diffuser panel10 b and the light sources 10 a having a relatively long distance fromthe point of gaze 38, and sets the distance between the diffuser panel10 b and the light sources 10 a having a relatively intermediatedistance from the point of gaze 38 at a relatively intermediatedistance. When the light source panel 10 shown in FIG. 3 is used, thelight transmission control unit 16 relatively increases the distancebetween the diffuser panel 10 b and the light guide members 10 e thatare arranged in correspondence with the light sources 10 a having arelatively short distance from the point of gaze 38, relatively reducesthe distance between the diffuser panel 10 b and the light guide members10 e that are arranged in correspondence with the light sources 10 ahaving a relatively long distance from the point of gaze 38 and sets thedistance between the diffuser panel 10 b and the light guide members 10e that are arranged in correspondence with the light sources 10 a havinga relatively intermediate distance from the point of gaze 38 at arelatively intermediate distance. When the light source panel 10 shownin FIG. 4 is used, the light transmission control unit 16 relativelydecreases the aperture ratio of part of the liquid crystal panel 10 f,which corresponds to the positions at which the light sources 10a havinga relatively short distance from the point of gaze 38 are arranged,relatively increases the aperture ratio of part of the liquid crystalpanel 10 f, which corresponds to the positions at which the lightsources 10 a having a relatively long distance from the point of gaze 38are arranged, and sets the aperture ratio of part of the liquid crystalpanel 10 f, which corresponds to the positions at which the lightsources 10a having a relatively intermediate distance from the point ofgaze 38 are arranged, at a relatively intermediate aperture ratio. By sodoing, as shown in FIG. 20, the state of the virtual image 31 may begradually changed from the blurry state to the clear state from theposition having a short distance from the point of gaze 38 to theposition having a long distance from the point of gaze 38.

2. Operation

FIG. 21 is a flowchart that shows an example of risk computing operationand lighting control operation that are executed by the vehicleinformation transmission system according to the present embodiment.

Step SA1: Measurement of External Environment

The object sensor 11 measures information about an object (such as apedestrian, a bicycle, an automobile and a blind spot) around thevehicle 1.

Step SA2: Recognition of External Environment

The risk computing unit 14a recognizes whether the condition around thevehicle 1 is a normal condition in which no object is present andreminding or warning is not required or a condition in which an objectis present and reminding or warning is required on the basis of theinformation about the object, which is measured in step SA1. Forexample, the risk computing unit 14a recognizes that the conditionaround the vehicle 1 is a normal condition when no object is present andrecognizes that the condition around the vehicle 1 is a condition inwhich reminding or warning is required when an object is present.

Step SA3: Computation of Degree of Risk

When it is recognized in step SA2 that the condition around the vehicle1 is a condition in which reminding or warning is required, the riskcomputing unit 14 a locates the position at which the object is presenton the basis of the information about the object, which is measured instep SA1. The risk computing unit 14 a estimates that an object of whichthe position cannot be located has a low degree of risk (i.e., estimatesthat the condition around the vehicle 1 is a condition in whichreminding is required).

For an object of which the position can be located, the risk computingunit 14 a calculates the distance between the object and the vehicle 1and the relative deceleration (which may be relative speed or relativeacceleration) of the object with respect to the vehicle 1. The riskcomputing unit 14 a estimates that the degree of risk is high (i.e.,estimates that the condition around the vehicle 1 is a condition inwhich warning is required) when the distance is short, and estimatesthat the degree of risk is low (i.e., estimates that the conditionaround the vehicle 1 is a condition in which reminding is required) whenthe distance is long. In addition, the risk computing unit 14a estimatesthat the degree of risk is low (i.e., estimates that the conditionaround the vehicle 1 is a condition in which reminding is required) whenthe relative deceleration of the object with respect to the vehicle 1 islow and estimates that the degree of risk is high (i.e., estimates thatthe condition around the vehicle 1 is a condition in which warning isrequired) when the relative deceleration is high.

Step SA4: Setting of Photostimulation Pattern

On the basis of the position at which the object is present, located instep SA3, and the degree of risk of the object, estimated in step SA3,the lighting control unit 15 consults a map shown in FIG. 22, whichdefines the correlation between the position and degree of risk of anobject and the projected position and projected area of light, todetermine the projected position (projected position in the horizontaldirection and projected position in the vertical (height) direction) andprojected area of light for notification and, where necessary,determines the projected position and projected area of light forattention allocation. For example, the projected position of light fornotification (i.e., the position onto which light for notification isprojected) is set at the left side when the position at which the objectis present is the left side, set at the front side when the position isthe front side and set at the right side when the position is the rightside. On the other hand, the projected position of light for attentionallocation is set at the right side when the projected position of lightfor notification is the left side, set at the left side when theprojected position of light for notification is the right side and isnot set when the projected position of light for notification is thefront side or both the right and left sides. In addition, the projectedarea of light for notification is increased during warning when thedegree of risk of the object is high and is reduced during remindingwhen the degree of risk of the object is low. On the other hand, theprojected area of light for attention allocation is reduced so that thedifference from the projected area of light for notification is distinctduring warning when the degree of risk of the object is high and isslightly reduced so that the difference from the projected area of lightfor notification is not so distinct during reminding when the degree ofrisk of the object is low.

On the basis of the degree of risk of the object, estimated in step SA3,and the statuses of color and luminance adjusted in accordance with themaps shown in FIG. 12 and FIG. 13 and stored in advance, the lightingcontrol unit 15 determines the color and luminance of light fornotification and, where necessary, determines the color and luminance oflight for attention allocation, which are different from the color andluminance of light for notification. In addition, the lighting controlunit 15 determines the amounts of variation per unit variation (theamounts of unit variation) in the color and luminance of light fornotification on the basis of the degree of risk of the object, estimatedin step SA3. For example, as shown in FIG. 23, the amounts of unitvariation in color and luminance are increased when a variation per unittime in the degree of risk is large, and the amounts of unit variationin color and luminance are reduced when a variation per unit time in thedegree of risk is small.

The lighting control unit 15 sets a lighting pattern for notification(reminding or warning), which includes the determined projectedposition, projected area, color, luminance and amounts of unit variationof light. When it is recognized in step SA2 that the condition aroundthe vehicle 1 is a normal condition in which reminding is not required,the lighting control unit 15 sets a normal lighting pattern, whichincludes the color and luminance for normal times and is different fromthe lighting pattern for notification, on the basis of the statuses ofcolor and luminance adjusted in accordance with the maps shown in FIG.12 and FIG. 13 and stored in advance.

Step SA5: Photostimulated Display

The lighting control unit 15 sets (corrects) the center position of thelighted light source panel 10 on the basis of a road shape, and on thebasis of the lighting pattern for notification or normal times, set instep SA4, and the set center position, the lighting control unit 15executes lighting control over each of the light sources 10a so as toattain the lighting pattern.

Thus, with the above described risk computing operation and lightingcontrol operation, in the situation shown in FIG. 24 in which warning isrequired (for example, in a situation in which an object 2 having a highdegree of risk is present at the left side when viewed from the driver),the virtual image 31 for notification set on the basis of the degree ofrisk of the object 2 is delivered at the left side, and the virtualimage 31 of a dummy for attention allocation, which is set so that thetotal of allocations of driver's attention to around the vehicle 1 isconstant, is also delivered at the right side so that the total of theattention allocations is constant, so, in the above situation, theuniform distribution of driver's attention to around the vehicle 1 maybe maintained (i.e., driver's attention may be uniformly distributed).

In addition, with the above described risk computing operation andlighting control operation, in a normal (safe) situation (for example, asituation in which no object is present around the vehicle 1) shown inFIG. 25 in which reminding or warning is not required, the virtual image31 for normal times, which has a low and soft color tone and isdifferent from the virtual image 31 for notification, is delivered at,for example, the left side, the center (front side), the right side orall of them when viewed from the driver. In addition, when a normalsituation changes into a situation shown in FIG. 26 in which the object2 appears and warning is required, the light level of part of the greenvirtual image 31 for normal times in the lowermost region, whichcorresponds to the position at which the object 2 is present or thedirection in which the object 2 is present (part of the lowermost regionat the left side in FIG. 26) is decreased, while the light level of thecorresponding part of the red virtual image 31 for warning in theuppermost region (part of the upper most region at the left side in FIG.26) is increased. The virtual image 31 may be regarded as a series oflight dots extending in the vehicle-width direction. The green virtualimage 31 and the red virtual image 31 are parallel to each other. Thevirtual images 31 may be displayed at a plurality of differentpositions, such as the A pillar, the sideview mirror, the meter panel,and the instrument panel. By so doing, when a normal situation changesinto a situation in which reminding or warning is required, it ispossible to more naturally remind or warn the driver without causing afeeling of strangeness and unexpectedness.

In addition, with the above described risk computing operation andlighting control operation, when the vehicle is running on a straightroad in a situation in which notification is required as shown in FIG.27, the center position C during lighting is set at (corrected to) thecenter (front side) when viewed from the driver in accordance with theroad shape, and, when the vehicle 1 is running on a right-hand curveroad as shown in FIG. 28, the center position C during lighting is setat (corrected to) the right side when viewed from the driver inaccordance with the road shape, and then the virtual image 31 fornotification is delivered on the basis of the set center position C. Byso doing, it is possible to remind or warn the driver within the rangethat does not fall outside the driver's visual field (a certain rangefrom the driver's direction of gaze).

In addition, with the above described risk computing operation andlighting control operation, in a situation in which the relativedeceleration V of an object 2 that is a preceding vehicle is low andreminding is required as shown in FIG. 29, the virtual image 31 forreminding, in which the amounts of unit variation are reduced, isdelivered, and, in a situation in which the relative deceleration V ofthe object 2 is high and warning is required as shown in FIG. 30, thevirtual image 31 for warning, in which the amounts of unit variation areincreased, is delivered, so it is possible to remind or warn the driverusing the details of lighting, which suit the relative relationshipbetween the vehicle 1 and an object.

3. Summary of Present Embodiment

According to the present embodiment, light from the plurality of lightsources 10 a arranged in an array (a plurality of rows or a plurality ofcolumns) in the light source panel 10 mounted at a predeterminedposition of the instrument panel 22 is projected onto a portion of thefront windshield 20, which corresponds to the position at which a riskobject (such as a pedestrian, a bicycle, an automobile and a blind spot)is present or the direction in which the risk object is present, using acolor, luminance, area, interval, or the like corresponding to thedegree of risk or the like of the risk object, to remind or warn thedriver. For example, in a conventional night view system, when apedestrian is detected by an infrared ray sensor during nighttime hours,the detected pedestrian is surrounded by a frame to be informed on ascreen; however, it is difficult for a driver to recognize thecorrespondence between details displayed on the screen and an actualsituation. However, according to the present embodiment, it is possibleto reliably notify the driver of the position or direction of a riskobject more easily and also to notify the driver without causing anyinconvenience and a feeling of strangeness.

In addition, according to the present embodiment, the luminance (appliedvoltage) and color of light from each light source 10 a are set on thebasis of the distance from the position at which the light source 10 ais arranged to the projected position of light from the light source 10a on the front windshield 20 and/or the angle formed by the frontwindshield 20 and the line segment that connects the arranged positionof each light source 10 a and the projected position of light from thatlight source 10 a. For example, the luminance of light is increased asthe distance between the light source 10 a and the correspondingprojected position increases. By so doing, light reflected from thevehicle body is more easily visually recognized by the driver and, as aresult, it is possible to improve information transmission efficiency.In addition, light may be adjusted to an easily recognizable position inaccordance with the driver's eye point.

In addition, according to the present embodiment, the light source panel10 includes the mechanism for adjusting the luminance of light (thedegree of transmission of light or the degree of blur of light) fromeach of the light sources 10a. Thus, it is possible to eliminateinconvenience due to intense light. For example, when the driver isprompted to locate a position or direction, the luminance of light isdecreased to blur the virtual image; whereas, when specific information,such as a character and an icon, is transmitted, the luminance of lightis increased to clearly deliver the virtual image. By so doing, itbecomes hard for the driver to focus on the virtual image, and thedriver is able to easily see a forward view. In addition, in the casewhere specific information is transmitted, the luminance of light isdecreased to blur the virtual image when the vehicle 1 is running at aspeed that exceeds a predetermined speed. By so doing, during stop ofthe vehicle, visual recognition through central vision is guided to makeit possible to provide detailed information; whereas, during vehiclerunning, visual recognition through peripheral vision is guided to makeit possible to transmit only the presence and position of a risk. Thatis, the amount and quality of transmitted information may be improvedduring stop of the vehicle; whereas the amount and quality oftransmitted information may be limited during vehicle running. Inaddition, only the light sources 10a that correspond to the projectedposition of light recognized by the driver are selectively decreased inthe luminance of light to partially blur the virtual image. By so doing,it becomes hard for the driver to focus on the virtual image that thedriver has viewed once, so the time during which an eye point isretained through direct vision may be reduced. In addition, as thequality and priority of transmitted information become higher, forexample, as the degree of risk around the vehicle 1 increases, theluminance of light is increased to clearly deliver the virtual image. Byso doing, important information may be reliably transmitted to thedriver. In addition, the direction of the line of sight, on which thedriver should place the most importance, is estimated from a road shape(curve), and the luminance of light projected in this direction isdecreased to blur the virtual image. By so doing, during cornering, itbecomes difficult for the driver to focus on the virtual image in thedirection of gaze, so a forward view is more easily seen. In addition,the luminance of light is adjusted on the basis of a distance from thecentral vision, to change the degree of blur of the virtual image. By sodoing, in consideration of human characteristics that a clearer shapemay be captured as it approaches the central vision, the amount andquality of transmitted information may be made more appropriate.

In addition, according to the present embodiment, when the position atwhich an object is present or the direction in which the object ispresent is notified, a virtual image for notification, which correspondsto the degree or the like of risk of the object, is delivered at aportion of the front windshield 20 corresponding to the position atwhich the object is present or the direction in which the object ispresent, and a virtual image for attention allocation, which isdifferent from the virtual image for notification, is delivered at aportion of the front windshield 20 corresponding to a position ordirection different from the above position or direction at or in whichthe object is present. For example, when a risk object is present at theleft side or the right side, the distribution of the details of lightingis adjusted (changed) on the basis of the degree of risk. By so doing,the driver is exactly prompted to locate an object, while driver'sattention to around the vehicle 1 may be uniformly distributed, that is,the uniform distribution of driver's attention to around the vehicle 1may be maintained to the same extent as that during normal times. Inaddition, when a plurality of virtual images are delivered at the sametime, light levels of the virtual images may vary in accordance with thedetails of risks. In addition, the driver is prompted to recognizediscontinuous separated positions not integrally but separately. By sodoing, attention may be appropriately allocated to the portions thatshould be recognized while prompting recognition of a wide range. Notethat, when information having high urgency is notified, a virtual imagefor notification, which corresponds to that information, may bedelivered earlier than a virtual image for attention allocation.

In addition, according to the present embodiment, even in a normalcondition, the light sources 10a for the left side, the center or theright side in front of the vehicle are constantly lighted using thedetails of lighting for normal times. By so doing, when a normalcondition changes into a notification condition, the driver may bereminded or warned without excessively highlighted light and a feelingof strangeness.

In addition, according to the present embodiment, the roughness of astepwise variation in the color and luminance of light is changed on thebasis of a variation in the degree of risk around the vehicle 1. Forexample, when a variation in the degree of risk around the vehicle 1 islarge, light is projected so that the amounts of variation in luminanceand/or color per unit variation increase, that is, the luminance and/orthe color roughly change; whereas, when a variation in the degree ofrisk around the vehicle 1 is small, light is projected so that theamounts of variation in luminance and/or color per unit variationreduce, that is, the luminance and/or the color minutely change. Thatis, the amounts of variation in the luminance and/or color of light arechanged on the basis of the correlation between the luminance and/orcolor of light and a risk. By so doing, a variation in the degree ofrisk may be clearly transmitted to the driver by changing the way offeeling a risk. In addition, the roughness of stepwise variation in thecolor or luminance of light is changed on the basis of the priority oftransmitted information. For example, when information having a highpriority is transmitted, light is projected so that the amounts ofvariation in luminance and/or color per unit variation increase, thatis, the luminance and/or the color roughly change; whereas, wheninformation having a low priority is transmitted, the amounts ofvariation in luminance and/or color per unit variation reduce, that is,the luminance and/or the color minutely change. By so doing, theimportance of information may be clearly transmitted to the driver.

As described above, the vehicle information transmission deviceaccording to the aspect of the invention is useful in automobilemanufacturing industry and is particularly suitable for transmission ofinformation to the driver using the vehicle body.

The invention claimed is:
 1. A vehicle information transmission devicethat prompts a driver for recognition of a certain object detected asbeing located at a position proximate to the vehicle, the vehicleinformation transmission device comprising: an electronic control unit,the electronic unit prompting both recognition of the certain object andrecognition of a position different from a position of the certainobject, so that the driver's attention is constant and uniformlydistributed, wherein in a case where the position of the certain objectis a left side with reference to a position of the driver, theelectronic control unit prompts recognition of a right side withreference to the driver as the position different from the position ofthe certain object; and in a case where the position of the certainobject is the right side with reference to the position of the driver,the electronic unit prompts recognition of the left side with referenceto the driver as the position different from the position of the certainobject, so that the driver's attention is also allocated by thecorresponding prompt at the side where the certain object is notdetected, while the driver's attention is being attracted by thecorresponding prompt at the side where the certain object is detected.2. The vehicle information transmission device according to claim 1,further comprising: a display that prompts recognition of the certainobject by projecting light onto a certain portion on a vehicle body, andthat prompts recognition of the position different from the position ofthe certain object by projecting light onto a portion different from thecertain portion on the vehicle body.
 3. The vehicle informationtransmission device according to claim 2, wherein the display isinstalled inside a vehicle, and the display projects light onto a frontwindshield.
 4. The vehicle information transmission device according toclaim 3, wherein the display is installed at an instrument panel.
 5. Thevehicle information transmission device according to claim 1, whereinthe position of the certain object and the position different from theposition of the certain object are spaced apart from each other.
 6. Thevehicle information transmission device according to claim 1, wherein amanner of prompting recognition of the certain object is different froma manner of prompting recognition of the position different from theposition of the certain object.
 7. The vehicle information transmissiondevice according to claim 1, wherein the vehicle informationtransmission device prompts recognition of the position different fromthe position of the certain object while prompting recognition of thecertain object.
 8. A vehicle information transmission device comprising:a first display portion that prompts checking of a right side withreference to a position of a driver; and a second display portion thatprompts checking of a left side with reference to the position of thedriver, wherein when checking of a certain object responsive to itsdetection is prompted at the right side or at the left side, the firstdisplay portion and the second display portion respectively also promptchecking of the left side or checking of the right side accordingly, sothat the driver's attention allocation is constant and uniformlydistributed, in a case where the position of the certain object is theleft side with reference to the position of the driver, the electroniccontrol unit prompts recognition of the right side with reference to thedriver as the position different from the position of the certainobject, and in a case where the position of the certain object is theright side with reference to the position of the driver, the electronicunit prompts recognition of the left side with reference to the driveras the position different from the position of the certain object, sothat the driver's attention is also allocated by the correspondingprompt at the side where the certain object is not detected, while thedriver's attention is being attracted by the corresponding prompt at theside where the certain object is detected.
 9. The vehicle informationtransmission device according to claim 8, wherein the first displayportion and the second display portion respectively project light ontodifferent portions of a vehicle body to prompt checking of the rightside and checking of the left side.
 10. The vehicle informationtransmission device according to claim 9, wherein when checking of thecertain object is prompted at the right side, an area of light projectedfrom the second display portion is smaller than an area of lightprojected from the first display portion, and when checking of thecertain object is prompted at the left side, the area of light projectedfrom the first display portion is smaller than the area of lightprojected from the second display portion.